Objective: To examine general and treatment-specific predictors of children's weight outcomes during a pediatric weight management trial.
Method: One hundred fifty overweight children-69.3% female; M body mass index (BMI) z score (z-BMI) = 2.21 ± 0.30-completed family-based behavioral weight loss treatment (FBT), followed by randomization to social facilitation maintenance (SFM) treatment addressing social support and body image; behavioral skills maintenance treatment (BSM), which extended FBT skills to maintenance; or a control condition with no maintenance treatment. Regression and mixed-effects repeated-measures analysis of covariance (ANCOVA) examined child and parent anthropometric, demographic, and psychosocial variables in predicting relative weight outcomes over short- and long-term follow-ups.
Results: Among FBT completers, lower child baseline z-BMI and age, and greater parent BMI reductions during FBT and baseline self-efficacy, predicted better child relative weight loss following FBT, F(6, 137) = 7.77, p < .001. Higher child-reported post-FBT eating pathology predicted greater relative weight loss in SFM than BSM or control from post-FBT to 2-year follow-up, F(4,255.88) = 3.48, p = .009, whereas higher parent-reported post-FBT social support predicted greater relative weight loss in BSM than control, F(2,141.65) = 3.28, p = .04. Lower parent-reported post-FBT behavioral problems predicted greater relative weight loss in SFM and BSM versus control, F(2,147.84) = 7.37, p < .001; higher problems predicted equivalent outcome across treatments.
Conclusion: SFM may improve weight outcomes for FBT completers with initially higher eating pathology, whereas extending FBT skills may be effective for those with higher familial support. These results suggest that certain pretreatment variables moderate the effectiveness of different pediatric weight control interventions. Further understanding these findings may help optimally match families to treatments.